A Plethora of Parakeets

Monk Parakeet, Myiopsitta monachus

Established in Austin in the early 1970s from escaped caged birds, Monk Parakeets (Myiopsitta monachus) also known as Quaker Parrots, are native to the temperate and subtropical regions of Argentina and surrounding countries in South America.  ‘Monks’ are often heard before they are seen, as their call is a loud and throaty chap(-yee) or quak quaki quak-wi quarr, and their sometimes startling screeches sound like skveet!  They have grown in numbers by being able to survive our mild winters, and as such have now been included on the official list of accepted Texas bird species. 

A colorful bird with bright green upper parts, pale grey forehead and breast with darker scalloped edges, and very light green to yellow under parts, Monks also have an orange bill, stiff dark blue flight feathers, and a long tapered tail.  Technically a parrot, it is this tail that makes them a parakeet, which is a term for small to medium sized species of parrots that generally have long tail feathers.

Monks are the only parrot that builds a stick nest, either in a tall tree or man-made structure, rather than using an existing hole in a tree.  They often breed in colonies, building a single large nest that has separate entrance holes for each pair.  In the wild these colonies can become quite large, with communal nests reaching the size of a small automobile! Also unusual for a parrot, these birds occasionally have ‘helper individuals’, typically grown offspring, which assist in feeding the young.  Highly intelligent and social birds, Monks can live anywhere from 15 to 30 years, and like other species of parrots kept as pets, they routinely develop quite a large vocabulary.   

Monk Parakeet Nest

Monk Parakeets readily adapt to urban neighborhoods, as they are an open woodland species.  A recent informal survey found over 65 nests in Austin, mostly in cell phone towers, tall telephone poles, and sports facility light poles.  Even if the nests are cleared out, many colonies return to the same place to rebuild their nest.  While mainly constructed out of willow branches, these nests may include man-made items such as rope, carpet, newspaper, and scraps of cloth.  The Monks’ diet consists of berries, tree buds, and seeds, all of which can be plentiful in both the native and non-native the tree species common in the Austin area.

The exact number of wild Monks in our area is unknown, and evidence of harm by feral colonies of Monks is disputed.  While they can be agricultural pests by eating fruits, grains, and other crops, they can also benefit local economies through birdwatching-based ecotourism.  It is also important to remember that tens of millions of parrots have been removed from the wild worldwide, and have been traded in greater numbers and for far longer than any other group of wild animals.  Many parrot species are still threatened by this trade, as well as by habitat loss, predation by introduced species, and hunting for food or feathers.  As such, let’s respect their existence and enjoy our plethora of parakeets!

Mysterious Moths

Luna moth, Actias luna

While much more numerous but not as widely studied as their close cousin the butterfly, moths are a large and fascinating group of insects.  Making up about 80% of the insect order known as Lepidoptera, most moths are active mainly at night, strangely attracted to light, and while some never eat, many species can live much longer than most butterflies and can even hibernate over the winter.

Cecropia moth, Hyalophora cecropia, caterpillar

Like butterflies, the lifecycle of a moth is comprised of an egg, caterpillar (larvae), pupa, and adult. The length of this cycle and each of its phases varies with each species, with some species producing as many as 10 broods a year.  Many moths have hairy bodies to help maintain the internal body temperature necessary for flight, and heat up their flight muscles by vibrating their wings, since they don’t have the radiant energy of the sun to assist them.  Sphinx moths, whose wings beat 70 times per second, have a top speed of 50 kilometers per hour, and even more amazingly, many pupate underground! Moths range in size from the micros that have wingspans of 3-4 millimeters to the female Cecropia moth, with a record wingspan of over 130 millimeters, the largest insect in North America. 

Cecropia moth, Hyalophora cecropia, cocoon

Moths are positively phototactic, or automatically move toward a source of light.  While the exact reason for this is unknown, interesting theories abound.  Some moths are known to migrate short distances, and may use the night sky to navigate.  They may use the moon as a primary reference point and have the ability to calibrate their flight paths as the moon moves across the night sky.  This may help orient them, and can also explain the disorientation they seem to experience when they unexpectedly ‘catch’ or fly above a light source that they think is the moon. It’s also possible that moths look at light as an escape route mechanism, where flying up (toward the light) signifies safety, and flying down (toward the darkness) signifies danger.

Cecropia moth, Hyalophora cecropia

Once they find an appealing source of light (preferring white versus yellow wavelengths), moths seem entranced by it.  Like humans, moth’s eyes contain light sensors, but unlike humans their dark-adapting mechanism responds much more slowly than their light-adapting mechanism.  This could mean that they may not want to leave the light since the dark renders them blind for so long, and might explain why they can be attracted to the light over & over again.  Lastly, since moths are generally nocturnal creatures, they may respond to the light like they would the rising sun, and settle in for a good day’s sleep.      

With so many thousands of moth species, even the largest can be difficult to identify.  Clues can be gleaned from their profile or posture, vein patterns in their wings, and even the time of night that they are most active.  Moths have antennae that are either feather-like or hair-like, with the male’s antennae being larger than the female’s.  This is beneficial for detecting the pheromones (a chemical signal that triggers a natural response from a member of the same species) released by the females from as much as 8 kilometers away!  

Imperial moth, Eacles imperialis

Polyphemus moth, Antheraea polyphemus

Some of our most beautiful nighttime jewels include the Cecropia, Imperial, Luna, and Polyphemus moths.  These large  moths, all members of the Giant Silkworm (Saturniidae) family, hold our greatest fascination. Cecropia larvae grow to about 4 inches in length, and you can often hear them as they eat.  Imperial moths emerge in September/October awash in yellow & purple. The luminescent green Lunas, like all Saturniidae, are born without a mouth – they never eat or drink, as their main purpose is to reproduce.  And the Polyphemus is named for the Greek Cyclops due to the large purple eyespot on each hindwing.  So the next time you’re up at night, wander outside by a light and see if you can spot some of these lovely creatures!

Magical Monarch Migration

Monarch male, Danaus plexippus

Most of us are aware of the typical life cycle of a butterfly – first an egg is laid on a food plant, a caterpillar (or larvae) hatches from the egg, once the caterpillar eats enough it  turns into a chrysalis, and shortly after a beautiful adult butterfly emerges.  However, unlike other butterflies, migration plays a key role in the Monarch’s lifecycle, and it is a fantastic migration at that!

Monarch caterpillar

Monarch chrysalis

Unlike most other insects in temperate climates, Monarch butterflies cannot survive a long, cold winter.  Instead, they spend the winter in one of two main roosting spots – those west of the Rockies travel to small groves of trees along the California coast, and those east of the Rockies fly further south to the forests high in the Chihuahua Mountains of Mexico.  

Butterfly Milkweed, Asclepias tuberosa

Austin is on the very eastern edge of this central flyway to Mexico, and in October/November large numbers of Monarchs work their way through Central Texas.  These butterflies were actually born on milkweed plants in Canada earlier in the summer.  Even though they look like summer adults, they won’t mate or lay eggs until the following spring.  Instead, their small bodies prepare for a strenuous flight.  As they migrate southwards, the Monarchs stop to nectar, and actually gain weight in the form of fat to fuel their flight and last them throughout their winter roost.  These butterflies wake up about mid-morning, gathering nectar from flowers in full bloom, and fly until sunset, covering distances up to 400 miles in a single day.  Although this generation of butterflies has never ventured into Mexico in the past, somehow they still find their way. 

Once they reach their wintering grounds in Mexico, the Monarchs roost in huge clusters that virtually drip off the evergreen trees, and feed on the nectar of native plants.  If they survive the winter, they will begin the trip back to Canada in late March or early April.  Although the same butterflies that winter in Mexico don’t survive long enough to see Canada once more, the next three generations carry on the lifecycle as they migrate north.  Each first through third generation lives only six to eight weeks, and it is this fourth generation -- the great, great grandchildren -- that complete the return journey back into Mexico.

Driven by seasonal changes such as temperature and day length, the migration of the Monarch is unique in all the world.  They travel up to a total of 3,000 miles -- much farther than all other tropical butterflies and they are the only butterfly species to make such a long, two-way migration every year.  Amazingly, they fly in masses to the same winter roosts, often to the exact same trees, but unlike other migrating species (such as birds and whales), it is their children’s grandchildren that return south the following fall.  

Now that you know a little something about their magical migration, stop to admire these amazing beauties as you see them flutter by you this fall on their way to their winter home in Mexico! 

Sn-outbreak!

American Snout, Libytheana carinenta

The change from late summer into early fall can trigger some unusual natural events, and at this time of year in Central Texas, we can often see periodic population explosions of the American Snout butterfly.

Often mistaken for migrating Monarch butterflies, the American Snout (Libytheana carinenta) is a medium-sized butterfly with a brown upperside, wings orange at the base, and white spots near the tips of the forewings.  Their underside is a mottled grayish-brown pattern, much like a dried, dead leaf.  Snouts are named for their elongated mouthparts, and when they hang from the underside of a branch, which they most often do, their ‘snout’ resembles the stem or ‘petiole’ of a leaf and their folded wings appear to be the dead leaf itself.  It’s the perfect camouflage for defense against avian predators. 

In the caterpillar stage, snouts are dark green with yellow stripes along the top and sides of their body, with two small, black tubercles on the top of their thorax.  These caterpillars feed on all hackberry species, but they prefer spiny hackberry.  While Austin is at the northernmost boundary of this plant’s range, it is close enough that we get to experience a ‘sn-outbreak.’  After a good rain, spiny hackberry plants (also known as granjeno or desert hackberry) grow numerous new leaves.  In response, the snout butterfly lays its eggs on these new leaves, which provides the fuel for a significant number of its caterpillars.  In Texas, it only takes 12 days to go from egg to caterpillar to adult butterfly.

Spiny Hackberry, Celtis ehrenbergiana

The ecology behind this event is related to several factors.  First, the population of snouts is positively correlated to the intensity and duration of dry periods that immediately precede significant rains.  These droughts seem to greatly diminish parasites that can harm and kill snout larvae.  Second, adult snouts wait out these long, dry periods by remaining in ‘reproductive diapause’, a state of arrested development/reproduction and decreased metabolism in response to the adverse environmental conditions.  This condition reverses when the rains arrive and trigger the third factor, new growth on the spiny hackberry host plants.  Female snouts will only lay eggs on this prolific new growth, and coupled with the lack of parasites, this creates a population boom.

Most often, sn-outbreaks occur in South Texas and Mexico, where the spiny hackberry is plentiful.  However, one of the largest recorded snout emergences occurred in late September of 1921, when over the course of 18 days more than 6 billion southeasterly-bound snout butterflies flew over San Marcos to the Rio Grande River.  That’s an estimated 25 million per minute!  While not every year is quite that spectacular, keep your eyes open about two weeks after a rain, and you should see region-wide migrations of snout butterflies as they waft by in pretty impressive numbers.